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The purpose of this study was to datermine the results of the first Wiktor stent implantations in bailout conditions. From December 1990 to July 1991, in a total of 10 centers, 69 patients presenting with threatened or total closure after balloon angioplasty each received the Wiktor stent in 1 coronary artery. in these 69 coronary arteries, a total of 72 stent deliveries were attempted and 69 were successful delivery success rate 95%). Delivery failure was treated conservatively in 2 patients and surgically in 1 patient. Emergency surgery was also performed in 2 patients, who after successful stent delivery showed progressive distal extension of the dissection section. In addition, 5 patients underwent elective surgery to avoid the possibility of stent thrombosis because the myocardial area at risk was considered too large. Postprocedural blood transfusion was performed in 6% of the patients, whereas stent thrombosis occurred in 10 of 59 patients (17%), resulting in 2 deaths. Finally, 65% of the patients had a successful stent implantation without major periprocedural complications. At 6 month follow-up, only 9% of the patients experienced recurrent angina, whereas a >50% arterial diameter narrowing was observed in 27% of the patients. Thus, the radiopaque Wiktor stent can be accurately and conveniently implanted in dissected coronary arterial segments. However, as for similar bailout devices, the number of thrombatic and blooding events remains high. (Am J Cardiol 1994;73:737-741)

Intracoronary stenting has been proposed as an adjunct to balloon angioplasty to improve the immediate and long-term results. However, late luminal narrowing has been reported following the implantation of a variety of stents. One of the studies conducted with the Wiktor stent is a prospective registry designed to evaluate the feasibility, safety and efficacy of elective stent implantation in patients with documented restenosis of a native coronary artery. To identify angiographic variables predicting recurrence of restenosis, the angiograms of the first 91 patients with successful stent implantation and without clinical evidence of (sub)acute thrombotic stent occlusion were analyzed with the Computer Assisted Angiographic Analysis System using automated edge detection. The incidence of restenosis was 44% by patient and 45% by stent according to the 0.72 mm criterion, and 30% by patient and 29% by stent according to the 50% diameter stenosis criterion. The risk for restenosis for several angiographic variables was determined using an univariate analysis and is expressed as odds ratio with corresponding confidence interval. The only statistically significant predictor of restenosis was the relative gain when it exceeded 0.48 using the 0.72 mm criterion (odds ratio 2.7, 95% confidence interval 1.1-6.4). Furthermore, the relation between the relative gain (increase in minimal luminal diameter normalized to vessel size) as angiographic index of vessel wall injury and relative loss (decrease in minimal luminal diameter normalized to vessel size) as index of neointimal thickening was analyzed using a linear regression analysis. A Pearson product-moment correlation coefficient of 0.38 (p

To assess the results of a conservative coronary angioplasty strategy in unstable angina pectoris, the records of 1,421 consecutive patients without previous myocardial infarction undergoing a first percutaneous transluminal coronary angioplasty (PTCA) between 1986 and 1990 were reviewed. Of these patients, 631 had unstable and 790 had stable angina pectoris. Only after an intense effort to medically control symptoms, the unstable patients underwent PTCA at an average of 15.4 days (range 1 to 76) after hospital admission. Primary clinical success was achieved in 91.7% of patients with unstable and in 94.4% of those with stable angina pectoris (p = not significant). In-hospital mortality rates were 0.3 and 0.1%, respectively (p = not significant). Nonfatal in-hospital event rates for acute myocardial infarction, cerebrovascular accident and coronary bypass surgery were only slightly higher in patients with unstable angina pectoris; however, the difference from the stable group was significant when all events were combined (9 vs S.9%; p

Intracoronary stenting has been introduced as an adjunct to balloon angioplasty aimed at overcoming its limitation, namely acute vessel closure and late restenosis. This study reports that first experience with the Wiktor[TM] stent implanted in the first 50 consecutive patients. All patients had restenosis of a native coronary artery lesion after prior balloon angioplasty. The target coronary artery was the left anterior descending artery in 26 patients, the circumflex artery in 7 patients and the right coronary artery in 17 patients. The implantation success rate was 98% (49 of 50 patients). There were no procedural deaths. Acute or sub-acute thrombotic stent occlusion occurred in 5 patients (10%). All 5 patients sustained a nonfatal acute myocardial infarction. Four of these patients underwent recanalization by means of balloon angioplasty; the remaining patient was referred for bypass surgery. A major bleeding complication occurred in 11 patients (22%): groin bleeding necessitating blood transfusion in 6, gastrointestinal bleeding in 3 and hematuria in 2. Repeat angiography was performed at a mean of 5.6 [+ or -] 1.1 months in all but 1 patient undergoing implantation. Restenosis, defined by a reduction of [is greater than or equal to] 0.72 mm in the minimal luminal diameter or a change in diameter stenosis from < to [is less than or equal to] 50%, occurred in 20 (45%) and 13 (29%) patients, respectively. In this first experience, the easiness and high technical success rate of Wiktor stent implantatino are overshadowed by a high incidence of subacute stent occlusion and bleeding complication. Although direct comparison with balloon angioplasty regarding the incidence of subsequent restenosis rate is not possible, the experience reported in this study compares favorably with data reported in other published reports.

To analyze the effect of the calcium antagonist diltiazem on coronary hemodynamics, epicardial coronary artery diameter, coronary blood flow and coronary blood flow velocity were assessed at baseline and after a 0.5 mg intracoronary bolus of diltiazem in nonstenotic coronary arteries of awake humans. Patients (n = 20) were first randomized to pretreatment with either placebo (n = 10) or isosorbide dinitrate (0.5 [Micro]g/kg/min infusion; n = 10), and coronary flow reserve was measured before and after administration of diltiazem. There were significant increases in epicardial coronary artery diameter (10%; p = 0.0001) and coronary blood flow (30%; p = 0.0001) in all patients after administration of diltiazem. Whereas basal coronary blood flow velocity increased only slightly (7%; p = not significant), there was a significant decrease in coronary flow reserve (10%; p = 0.004). Increases in coronary diameter and blood flow after diltiazem were comparable in patients pretreated with placebo or nitrates. However, the decrease in coronary flow reserve was significant only in patients pretreated with placebo (19%; p = 0.0008). This reduction in coronary flow reserve could be due to 'raising the floor' (increased baseline coronary blood flow) or 'lowering the ceiling' (reduction of maximal coronary blood flow). (Am J Cardiol 1991;68:1633-1637)

The safety of the combination of heparin and ridogrel therapy and its antiplatelet efficacy was examined in the setting of percutaneous transluminal coronary angioplasty (PTCA). In 32 patients without known aspirin intake for 10 days before PTCA, therapy with ridogrel (300-mg intravenous bolus) was begun just before PTCA and continued orally at a dose of 300 mg twice daily until discharge. Heparin was administered as a 10,000 IU bolus dose before PTCA and followed by an intravenous infusion at a rate of 1,000 IU/hour for 24 hours. Bleeding problems at the arterialentry site occurred in 13 patients, which required a blood transfusion in only 2 patients. One patient underwent emergency bypass surgery without specific problems of hemostasis. Ridogrel virtually eliminated thromboxane [B.sub.2] from the serum (29,2900 [+ or -] 6,555 pg/0.1 ml before vs 63 [+ or -] pg/0.1 ml at 2 hours after ridogrel), with a concomitant increase in serum 6-keto-prostaglandin [F.sub.1[alpha]] (511 [+ or -] 34 pg/0.1 ml before vs 1,190 [+ or -] 146 pg/0.1 ml at 24 hours after ridogrel). There were no acute reocclusions in the ridogrel-treated patients, whereas acute reocclusions occurred in 5.6% of the patients taking the standard aspirin + heparin regimen during the same period. Furthermore, at 6-month clinical follow-up patients treated with ridogrel compared favorably with those receiving standard treatment. (Am J Cardiol 1991;68:463-466), Percutaneous transluminal coronary angioplasty (PTCA) is a technique used to dilate (widen) the coronary arteries, which supply blood to the heart. PTCA is used in the treatment of conditions such as atherosclerosis, in which cholesterol-rich deposits narrow the coronary arteries, diminishing the cardiac blood supply. While this therapy is quite effective, 2 to 11 percent of patients undergoing PTCA suffer reocclusion shortly after the procedure. One strategy for preventing reocclusion after PTCA has been the administration of drugs that prevent adhesion of blood platelets to the arterial wall (the precipitating factor in initiating reocclusion); however, the drugs currently available are not completely effective. A newly available drug, ridogrel, has been proposed as a more effective antiplatelet drug for use in this setting. This agent acts by inhibiting key enzymes involved in the platelet-initiated clotting process. To evaluate the utility and safety of ridogrel, a study involving 32 eligible patients (of 352 potential enrollees) referred for PTCA were administered either ridogrel and heparin or aspirin and heparin immediately after PTCA. (Aspirin and heparin are anticlotting medications.) Biochemical measurements indicated that ridogrel virtually eliminated blood levels of the enzymes on which it works. None of the patients treated with ridogrel suffered reocclusion after PTCA; 5.6 percent of the aspirin and heparin-treated patients did. At six-month follow-up, both groups of patients showed similar (low) levels of disease. (Consumer Summary produced by Reliance Medical Information, Inc.)

To determine the relevance of recent refinements in angioplasty technology to our particular practice, the records of 507 consecutive patients undergoing a first percutaneous transluminal coronary angioplasty (PTCA) at our center between October 1988 and May 1989 were reviewed. At the time of PTCA, 41% of these patients had class IV angina and 44% were identified as having multivessel disease. Dilatation was attempted in 734 lesions (mean 1.5 per patient), of which 95 (13%) were chronic total occlusions. Overall, 69% of the 734 lesions were judged anatomically complex, and, in dilating these lesions, a rail-type device was used almost exclusively. Successful dilatation was achieved in 659 of the 734 (90%) attempted lesions. There were low incidences of the major complications of death (0.4%), myocardial infarction (1.8%) and emergency bypass surgery (1.8%). Acute rethrombosis occurred in 54 patients (11). in these patients, initial strategy of repeat dilatation was successful in 38 of 47 patients (81%). Overall, primary clinical success at PTCA was achieved in 480 patients (95%). At a mean follow-up of 7.5 [plus or minus] 1.5 months in 497 of the study patients, the event-free rate (freedom from cardiac death, myocardial infarction, repeat PTCA or coronary bypass surgery or recurrence of severe [class ill to IV] angina) was 71%. in conclusion, despite the often complex coronary disease in patients currently presenting to our center, a high initial success rate and acceptable short-term outcome of PTCA was achieved. (Am J Cardiol 1991;67:253-258), Coronary artery disease (CAD) involves stenosis (narrowing) of the arteries supplying the heart with blood, to the extent that cardiac blood flow is compromised. This is usually caused by the formation of fatty atherosclerotic plaques on the inner surface of the arteries. A common treatment for CAD is percutaneous transluminal coronary angioplasty (PTCA), in which a catheter with an inflatable balloon tip is passed through the blood vessels to the occluded region of the coronary arteries, inflated (distending the narrowed region to restore blood flow), and removed. In recent years, improved maneuverability of the catheter system has increased the success rate for this procedure. To obtain an overview of how successful the use of one particular type of angioplasty device (the rail-type dilatation system) has been, the records of 507 consecutive patients undergoing their first PTCA at a Belgian cardiology practice between October 1988 and May 1989 were reviewed. At the time PTCA was performed, 41 percent of the patients had very severe angina pectoris (chest pains resulting from the CAD), and 44 percent had CAD afflicting two or more coronary blood vessels (multivessel CAD). Angioplasty was attempted on 734 narrowed arterial segments (an average of 1.5 per patient); 95 percent of these were total chronic occlusions. Successful restoration of blood flow was obtained in 90 percent of the cases. Low incidence of death (0.4 percent), heart attack (1.8 percent) and the need for emergency bypass surgery (1.8 percent) was noted. Recurrence of the blockage was seen in 11 percent of the patients; 81 percent of these were successfully treated with a repeat PTCA procedure. At 7.5-month (average) follow-up, 71 percent of the procedures were judged to have been successful (i.e. no incidence of cardiac death, heart attack, repeat PTCA, bypass surgery, or recurrence of severe angina pectoris). (Consumer Summary produced by Reliance Medical Information, Inc.)

To investigate the antiischemic efficacy of intravenously administered diltiazem, 42 patients were randomlY allocated to receive placebo or active treatment before 1-vessel percutaneous transluminal coronary angioplasty (PTCA). The development of myocardial ischemia was studied using subjective (pain) and objective electrocardiography) parameters. Pretreatment with intravenous diltiazem resulted in a significantly delayed onset of ischemic pain and ST-segment elevation; these variables also returned to baseline earlier after balloon deflation. Thus, intravenous diltiazem prevents or delays the onset of myocardial ischemia during repetitive transient coronary occlusions; improvement of the myocardial blood flow distal to the coronary occlusion or impedance of calcium entry into the ischemic cell are considered as possible mechanisms. Because PTCA is increasingly used in patients with poor left ventricular function and more extensive disease, and because recent evidence suggests that better PTCA results could be obtained by the use of longer inflation times, the addition of diltiazem to the classic armamentarium could be beneficial. (Am J Cardiol 1989;64:1103-1107), Percutaneous transluminal coronary angioplasty (PTCA) is a procedure for treating narrowed coronary arteries, which are the major blood vessels that bring blood to the heart. A catheter or tube-like structure with a small inflatable balloon is inserted into the narrowed portion of the artery, and the balloon is inflated, thereby mechanically dilating the narrowed coronary artery. In PTCA, inflation of the balloon causes transient occlusion, or blockage, of the coronary artery. This leads to regional ischemia, or insufficient blood flow to specific portions of the heart. Medications can be given before PTCA to reduce or prevent regional ischemia. The anti-ischemic effect of the drug diltiazem was assessed in 42 patients who were scheduled to undergo PTCA; half the patients received pretreatment with diltiazem while the other half received an inert placebo. During the PTCA procedure, chest pain and changes in the electrocardiogram, a recording of the electrical activity of the heart, were used as indicators of ischemia. Pretreatment with diltiazem delayed the onset of pain and ECG changes associated with ischemia, and both of these indicators returned to normal after deflation of the balloon more quickly with diltiazem than without. The results show that intravenous diltiazem delays the onset of myocardial ischemia during repetitive and brief blockage of the coronary arteries. Diltiazem may exert its effects by improving blood flow beyond the blocked portion of the coronary artery, or by blocking the entry of calcium into the ischemic cell; diltiazem is a calcium blocking agent. Thus, diltiazem may be a useful medication for delaying the onset of ischemia in patients undergoing PTCA; it may be particularly helpful if longer balloon inflation periods (which may prove to be more effective than briefer periods) are utilized in the future. (Consumer Summary produced by Reliance Medical Information, Inc.)